Questions
About Your Community: Residential Wood Combustion

Indoor and outdoor wood-burning appliances and fireplaces may emit large quantities of air pollutants. Research shows that breathing wood smoke is not healthy. Wood smoke contains hundreds of chemical compounds, including nitrogen oxides, carbon monoxide, organic gases, and fine particles (also known as particulate matter or PM). Even limited exposure to smoke can be harmful to human health, particularly to the health of children, the elderly, and those with chronic conditions. Fine particles (i.e., particles smaller than 10 microns or about 30 times smaller than a human hair), can aggravate heart or respiratory problems, such as asthma, in people of all ages. More information on health effects of exposure to wood emissions is available at the EPA website http://www.epa.gov/burnwise/

Are there regulations in place?

Wood burning is a significant contributor to air pollution in many urban and rural areas, and EPA (as well as states and many municipalities) have taken steps to reduce air pollution from this source.

For indoor wood-burning appliances, EPA has certification requirements that govern the manufacture and sale of certain units. Specifically, indoor free-standing wood stoves and fireplace inserts sold after July 1, 1992, must meet "phase 2" particulate emission limits of 4.1 g/hr for catalytic stoves and 7.5 g/hr for noncatalytic stoves. These requirements, however, do not cover indoor masonry fireplaces used for aesthetic purposes. In addition, EPA regulations do not prohibit the use of stoves manufactured before 1992, nor do they address permitting or installation of woodstoves. More information on wood stoves and fireplaces is available at the EPA website http://www.epa.gov/burnwise/ .

For outdoor wood-burning heaters, EPA recently developed a voluntary two-part strategy to reduce harmful emissions. These heaters (called outdoor wood-fired hydronic heaters (OWHHs), or "outdoor wood heaters," "outdoor wood boilers," (OWBs) or "outdoor furnaces") are mainly used by homeowners to heat houses, hot water, and swimming pools, and by businesses for operations such as greenhouses. The voluntary program includes an MOU between EPA and manufacturers to produce cleaner units (about 70% less emissions) by April 2007, new text for OWH labels and hang tags, as well as Owner's Manual text for unit operation and maintenance. For the second part of the strategy, EPA worked with The Clean Air Association of the Northeast States (NESCAUM) to develop a model rule that states, tribes and local authorities may elect to use, in whole or in part, if they choose to regulate outdoor wood-fired hydronic heaters. More information on OWHHs is available at the EPA website http://www.epa.gov/burnwise/.

In general, States and municipalities have lead roles in regulating wood-burning activities. Some states and municipalities have developed regulations or voluntary programs to address the fact that most stoves are still not EPA-certified and, in some cases, to prohibit use of woodstoves during certain air-quality conditions. Although most regulatory activity has occurred in the western part of the country, eastern states are increasing their focus on wood-burning activities. Until recently, the focus in New England has been on outdoor burning of trash and household waste, but New England states are increasing their focus on outdoor wood-fired heaters, which are almost always much worse polluters than woodstoves. In April 2007, Vermont became the first New England state to enact a regulation for outdoor wood heaters, and Maine is developing a similar regulation. Others may follow in the near future.

How can you reduce the impact of your fireplace or wood stove?

Equipment: Consider replacing an older wood-burning appliances with a new, efficient, EPA-certified wood or pellet stove, or install a catalytic combustor (just like the one in your car's exhaust system) on your existing stove. EPA-certified stoves are easy to identify because they carry a special label and hang tag. Because these stoves are cleaner burning, you will need to clean your chimney or stove pipe less often, and will reduce the probability of a chimney fire. A list of EPA-certified wood stoves and fireplace inserts is available at http://www.epa.gov/Compliance/resources/publications/monitoring/index.html.

If you are considering purchasing an OWHH, be aware that these heaters commonly produce excessive amounts of smoke and can negatively impact nearby residences. A list of cleaner burning OWHHs is available at http://www.epa.gov/burnwise/.

Operation: The way you operate your wood-burning appliance affects its efficiency and, in turn, the amount of pollution and creosote created. Smoldering fires give off much more pollution than small, hotter fires. To encourage a cleaner burning fire, use wood that has been split and dried for at least six months. Be aware that you shouldn't burn garbage, trash, or treated woods such as plywood or pressure-treated wood as these materials contain chemicals that, when burned and inhaled, are hazardous to your health. More information on how to burn wood efficiently and safely is available at the EPA websites http://www.epa.gov/woodstoves/efficiently.html and http://www.epa.gov/woodheaters/bestpractices.htm

Who should you contact if you have questions?

Most problems with wood smoke are addressed at the state or local level, so you should contact your state environmental agency and your municipal offices, such as the Fire Department and Board of Health) to find out what wood-burning regulations, ordinances, and bylaws may apply in your area. For example, the Fire Department may have requirements for residents to register woodstoves or to conduct periodic inspections. As mentioned above, some New England states have developed (Vermont) or are developing (Maine) regulations for outdoor wood heaters and others may follow in the near future.

For more information about wood combustion and PM: Alison Simcox (simcox.alison@epa.gov)
(617) 918-1684